Motorists warned as wholesale petrol price reaches high

Motorists face a costly Easter, as petrol prices are expected to jump to as much as $1.60 a litre in the next two weeks.

"Some signboards across the country will be showing prices over $1.60," Commsec economist Savanth Sebastian told 7News on Tuesday.

"CommSec expects prices to rise by as much as three cents a litre over the next fortnight, taking the national average prices above $1.50 a litre for the first time in over three years," he said.

"Unfortunately for motorists there are no signs that conditions are likely to get any better over the next couple of weeks," he said.

"The potential threats to oil supplies in the Middle East and improving economic conditions in the US have been the key drivers behind the surge in global oil prices."

The national average wholesale, or terminal gate, unleaded petrol cost hit a three-and-a-year half high in the past week.

The wholesale price was up 3.0 cent a litre to 132.3 cents a litre, its highest since October 20, 2008.

In Australian dollar terms, the price for Singapore gasoline rose by $1.40 to a three-and-a-half year high of $129.75 a barrel.

Australia's fuel prices are based on the Singapore benchmark cost as the city-state is the regional refining and distribution centre.

Mr Sebastian said the impact of sustained higher fuel prices would have a "dampening" effect across the economy.

"Retailers already have to contend with the effects of the weather on seasonal spending and consumer conservatism," Mr Sebastian said.